Characteristics of Unsteady Flow Wind Tunnel for OWC Wave Turbine

In recent years, the attention has been focused on renewable energy, and the ocean wave energy is expected to be one of the effective renewable energy in Japan. Wave power generation is classified into oscillating water column type, movable bodies type, and overtopping type according to the structural type. In this study, the oscillating water column type is considered that the oscillating air flow produced by the wave drives the bi-directional turbine. We proposed the new turbine for this type. It needs the test equipment to check the performance of the turbine in oscillating flow. There are several types of test equipment for wave turbine research, but they are not sufficient for our turbine test, such as large scale, high cost and complicated mechanics. We have developed a wind tunnel for the oscillating air flow test of turbine that can easily generate an oscillating flow at an arbitrary period. It has a simple structure in which a rotating butterfly valve with variable speed is installed at the exit of the wind tunnel. It is easily generated a short cycle oscillating flow. The period and amplitude of the flow can be changed independently